9 inch rebuild, pinion preload process?

[brushwolf]

I am rebuilding a 1961 Galaxie 9 inch differential to use in a 68 Torino. It has the large 4" pinion seal the same as a 57.  Watched numerous videos and searched a lot but still find most people are setting 8 inch or 9 inch pinion preload with the seal in. But numerous people say that is wrong and pinion preload is supposed to be done without the seal.

So if you did set preload with no seal using the old nut until the right preload is reached on the new crush collar, then remove the old nut, install the seal, install new pinion nut....

How are you supposed to get the preload back to exactly where it was since now you will have added drag of the seal? And when you install the new pinion nut it may differ some tiny dimensional amount as well as have less or more resistance in the threads.

I have read there is no specific torque amount on the nut, preload is the critical factor. I have a couple of the Ratech design crush collars that are supposed to be a little easier to crush and several new stock type crush sleeves on hand as well.

So,put the new pinion seal and new nut on to start with and add a few inch pounds to the suggested 25 inch pound preload for the new pinion bearings to allow for the added drag of the new seal?

Or no seal, old nut, torque pinion nut in foot pounds until pinion inch pound rotationql preload value reached, pull yoke back off and install seal and new nut and tighten until what I think the old pinion nut was torqued to before pulled back apart? Which I suppose I could perhaps do by gradually increasing the torque settings on my wrench until it reaches the same torque as the old nut and using that value.

Getting frustrated with this.

[brushwolf]

Just read Rich's similar thread which was interesting. I have usually just swapped entire axles previously too, or just the carrier and I have installed a couple pinion seals the thread counting method.

But this one I was replacing all the bearings too, so a complete teardown and trying to do it right. My axle housing and rebuilt brakes look so Purdy, waiting for the 4+" seal to arrive so I can finish the carrier assembly. With all the wrong parts I ordered I should be able to do another one with a later year carrier while I am it.

Over the years I too have avoided this, but am finally going to tackle it from end to end and see how it works out. The Ratech sleeve allegedly begins to crush at 175 ft lbs, so will probably use that instead of the stock piece that needs over 300 ft lbs. Don't think my vise would tolerate quite that much. I have a Milwaukee 18 volt impact that could probably jack the torque up that high, but impact wrenches allegedly rattle the bearings enough to cause premature failure, so going the long pipe/bar route, initially at least.

[gasman826]

I felt the same frustration with the service manual setup instructions...the 'catch 22' of using a one-time crush sleeve twice.  This is one of the reasons I set the pinion pre-load with a shim kit and toss the crush sleeve.

[brushwolf]

Well, my three new 4+ inch diameter early pinion seals arrived from Hawk Rod (Ebay) today ($42 for 3 seals including shipping).

So will try the incremental torquing with old pinion nut and without the seal and arrive at the suggested new pinion bearing preload of 25 inch pounds, note the torque reading that was required on my foot pound torque wrench to reach that preload.

Then take the yoke back off and install the new seal, tighten the yoke back up with the new nut and new seal installed, (rtv on the yoke splines) and see afterward how much pinion rotation force required changes on the inch pound torque wrench from the seal added, but with the new pinion nut torqued the same as initially.

Being I have 3 stock crush collars and 2 Ratech crush collars I should be able to get a satisfactory result in 5 tries. If not I will order the pinion shim set instead.

[brushwolf]

Well, 1st attempt was a miss.  At only 55 ft lbs torque on the pinion nut I already had 40 inch lbs rotating preload.  Every video I saw it showed there is still visible play when the pinion nut is on just far enough for inner bearing races to contact the crush sleeve.

Not me. As soon as the pinion nut snugged up it immediately showed excess turning resistance. Took it apart took out the bearings and races to make sure they were not wrong. They were not. Ratech crush sleeve had not changed size. Tried it all over again with factory crush sleeve. Same results, Excess pinion resistance at about 50 lbs.

Also pulled pinion carrier from 63 axle that has the 3 inch seal. Took bearings and races out of that and those bearing numbers also match both new bearings removed from the 61 (possible 57) WAB carrier.

So I don't know what the heck the problem is, going to do some brake lines on the 61 Sunliner that I am giving to my oldest son once complete. Maybe clean up the 63 pinion support since I have second pair of new pinion bearings and see what happens with that...

[RICH MUISE]

I'm still looking for someone to do mine. What you're going thru is exactly why I don't want to bring it to my regular guy. I just add fluid every few K.

[brushwolf]

I gave up on both the factory crush sleeve and the Ratech version. Put in the shim kit instead which will allow any future seal replacement without any more than removing the yoke.

Still took many attempts and some dumb mistakes like not locking torque wrench setting, mixing up shim thicknesses and deburring the shim edges cuz they have some edge imperfections that can throw everything off. But it should be right now.

Finally got to the 20 inch lbs for new bearings without seal at the recommended 125 ft lbs on pinion nut and then assembled with seal, rtv on yoke splines and under new pinion nut. I was curious how much the seal being in and new nut on. It changed by 10 inch lbs just adding the new lubed seal which was way more than I expected.